Tendon implants: primary and secondary usage.

The staged tendon grafting technique has definite advantages in reconstructive hand surgery. The benefits are realized in the more severely injured flexor tendon systems (Boyes' grades 2 to 4). The results obtained in these cases compare favorably with those achieved by primary tendon grafting in less severe grade 1 cases. This is made possible for the following two reasons: First, the inert nature of the implant allows numerous auxiliary procedures to be done at stage I, such as digital neurography, osteotomy, capsulotomy, scar resection, and pulley reconstruction. This can be done without fear of profuse formation of adhesions. Second, the passive gliding of the implant forms a pseudosynovial sheath, which provides a nutritive and physiologic bed for the autograft tendon at stage II. The operative technique has been presented and the postoperative care has been outlined. It cannot be overstressed that a good working relationship between the surgeon, hand therapist, and patient is of paramount importance to the success of the final result. Work on a prototype active gliding tendon prosthesis is described with details of the concepts and biomaterials involved in its development.